1. Field of the Invention
The present invention relates to an improvement in poles, markers and the like provided with a device for linking to the ground with breaking point, in particular anti-parking posts or vertical signalling markers used in road signalling.
2. Description of the Related Art
It is relatively expensive to replace markers and posts damaged further to a shock by a vehicle, insofar as not only must the damaged part be replaced, but it has to be unsealed and the replacement part sealed.
In the past, it has therefore been proposed to fix the signalling markers or posts with the aid of a ground-linking device comprising a breaking part, so that, in the event of shock by a vehicle, only the linking piece or one of its elements is deformed or broken. It follows that, in principle, only the linking piece and/or the corresponding element are to be replaced.
U.S. Pat. No. 3,340,531 in particular discloses such a linking device. This document provides fixing the pole to the ground via a sealed base having a hollow tube with the diameter of the pole, the link between this hollow tube and the pole being ensured by a linking piece which is placed, half in this hollow tube and half in the pole. This linking piece presents a median circumferential thin section intended to form the zone of deformation or of rupture. This linking piece may be pierced in its length so as to receive a sling intended to maintain the pole and the base together when the linking piece has broken. The major drawback of this device consists in the risk of damaging the opposite edges of the pole and the base. In effect, in the event of a considerable shock, bringing about complete rupture of the linking piece, the edges of the pole and of the base may violently strike one another or part of the linking piece.
U.S. Pat. No. 3,912,405 discloses another device of this type, comprising a linking piece of which a part is interposed between the pole and the tube sealed in the ground, having the same diameter as the latter but having a thinned rupture zone. Inside this linking piece there extends a flat iron element intended to maintain the sealed tube and pole together after rupture of the linking piece. The geometry of this flat iron element is not favourable to correct functioning of this device apart from a shock perpendicular to the plane of this piece.